#include <iostream>
#include <vector>
#include <string>

using namespace std;

class Solution {
public:
    void reverseString(vector<char>& s) {
        for (int i = 0; i < s.size() / 2; i++){
            swap(s[i], s[s.size()-1-i]);
        }
    }
};

int main(void)
{
    Solution su;
    // vector<char> vec/*  = {'1', '2', '3'} */;
    vector<char>vec = { '5', '2', '3' };
    su.reverseString(vec);
    return 0;
}
